CORVALLIS — One game — one unforgettable game — separates Oregon and Oregon State in the standings as the rivals prepare to face each other in tonight's Pac-12 opener at Gill Coliseum.

"I feel the Towson game is, and will be, extremely important for us,'' said OSU coach Craig Robinson of his team's humbling 67-66 overtime loss last weekend to a team that went 1-31 last season.

There was never a danger of Oregon State (10-3) looking past Oregon (11-2) in the 338th Civil War matchup (7 p.m. on ROOT), but now the Beavers are taking a harder look at themselves as they put their home-court advantage and experienced backcourt up against Oregon's stingy defense.

"It actually might be better for us that we had that,'' said guard Roberto Nelson, the Beavers' leading scorer (15.8 points) of the loss. "We were getting a little ahead of ourselves."

The Beavers were 19 points ahead of Towson but followed that misstep with a 25-point win over Texas-Pan American. Guard Ahmad Starks, trying to grab hold of that leadership role after a less-than-inspired December, offered up his shoulders.

"The last few games, I was basically playing down to the level of competition,'' said Starks who had 21 points Saturday after scoring a total of 24 in the previous five games. "I can't do that, as far as being a leader and just being a good player. I let my teammates down, and the loss — I took all the blame for that.''

Nelson and the accountable Starks have played a total of eight Civil Wars — eight more than Oregon's starting backcourt of Dominic Artis and Damyean Dotson, and that's a factor not lost on Ducks forward E.J. Singler, who seemingly has played in a good chunk of the 337.

"It's a different season, it's a different buzz in the building," said Singler, a former South Medford High star, who is aware that Robinson's 1-3-1 zone can give younger players fits. "They're a really long, athletic team, and they play that weird defensive scheme. If you're not used to it, it can bother you a little bit." (Artis and Dotson) have probably never seen anything like it. Hopefully they can learn it in practice instead of learning it in the game."

The Beavers, 11th in the league in scoring defense (67.7 points) are still a work in progress as they go from "weird'' to man-to-man. Both Robinson and Starks gave the team defense a seven on a scale of 1 to 10.

"I feel like it has gotten better,'' Starks said. "We've gotten better over the years, but we still have to lock in and get the stops, make the plays, make the rotations and we'll be good. Give us a seven. We want to get to a 10 by Sunday."

Let's give the Ducks a nine. They have held five opponents below 50 points and are allowing 60.4 points per game — fourth in the Pac-12.

"I like the way we're trying to guard,'' said Altman, whose early season issues are on the offensive end, although the Ducks showed they can outscore a good team in an 83-79 win at No. 18 UNLV.

Tonight's game could feature two of the top three rebounders in the Pac-12: Oregon State's Eric Moreland (11.2) and Oregon's Arsalan Kazemi (10.0), although Kazemi is questionable because of a concussion.The Beavers, of course, are playing without center Angus Brandt, who is out for the season after ACL surgery.

"Angus, I've always had an appreciation for his game,'' Altman said. "I like how rugged he plays and his ability to pick and pop, and he spreads the floor out pretty good. It's a good team, just not quite as deep as it would have been."

Robinson, who is starting true freshman Jarmal Reid at forward and bringing Devon Collier (14.8 points) off the bench, said he's only now feeling comfortable with his rotation in the wake of the injury Brandt suffered a month and a half ago. It also created a leadership void, as Brandt and Joe Burton were the Beavers' only seniors.

"Our team leadership is Angus, and he's not out there,'' Robinson said. "Ahmad taking responsibility and accountability for his play, or lack thereof in his mind, is great leadership stuff for him, and it helps the team, too.''

Now the Beavers, whose nonconference highlight was a six-point loss to No. 10 Kansas, hope Starks plays up to the level of competition.